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An Analysis of Operational Effects of Adjacent Double Roundabouts (쌍구형 회전교차로 도입에 따른 운영효과 연구)

  • Kim, Nohhyun;Kim, Myungsoo
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.16 no.6
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    • pp.42-52
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    • 2017
  • This was a study on the ultimate effect and characteristics of introducing a roundabout through a review of literature on the subject of roundabout. In order to examine an effect produced when roundabout is substituted for ordinary signal-controlled intersection operated at Daego Five-way Intersection and Seongmo Five-way Intersection located in Junggu, Daejeon Metropolitan City, site to be studied, the produced effect was analyzed through comparison between before and after introducing roundabouts in series at Daego Five-way Intersection and Seongmo Five-way Intersection by using microscopic traffic simulation program VISSIM widely used for analyzing an effect of roundabout based on a survey of geometric structure, traffic volume and signal interval on the site. As mentioned above, when Daego Five-way Intersection and Seongmo Five-way Intersection was changed to roundabout, a positive effect was produced on average speed and delay time in comparison with the existing status. It is possible to expect that roundabout can be more efficiently operated when 2 places on the site are changed to double roundabout than when separately changed to roundabouts.

Effects of Grazing on a Pasture Consisted of Different Combination of Tall Fescue and Legumes on Animal Production and Health in Dairy Heifers. IV. Effect on reproductive efficiency and disease-outbreak of grazing holstein heifer. (혼파방목지에서 Tall Fescue와 두과목초 조합이 가축생산성과 질병에 미치는 영향 IV. 방목젖소의 번식효율 및 질병 발생에 미치는 효과)

  • 장덕지;김중계;정창조;김규일;김문철
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.17 no.3
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    • pp.213-222
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    • 1997
  • This study was carried out to investigate the reproduction efficiency and disease of Holstein heifer grazed on mixed pasture desighed with association of tall fescue and white clover cultivar (3 treatments = TI : Tall fescue Fawn + White clover Regal + Orchardgrass + Perennial ryegrass, T2 : Tall fescue Roa + Ladino clover Regal + Orchardgrass + Perennial ryegrass, T3 : Tall fescue Roa + White clover Tahora + Orchardgrass + Perennial ryegrass) on reproduction efficiency and disease in Holstein heifers, ftom April 1994 to November 1996. The results are as follows: 1. Erythrocyte counts, hemoglobin and packed cell volume of hematological values were $8.12\times10^6/{\mu}\ell, 9.9g/m\ell and 30.6m\ell/100m\ell$ respectively. While those were decreased to $4.84~5.93 \times10^6/{\mu}\ell, 7.0~7.8g/100m\ell and 22.8~28.3m\ell/100m\ell$, on pastuage (May-August), WBC counts was increased from $14.4\times10^3/{\mu}\ell to 14.0~18.3 \times 10^{3/\mu\ell}$ on pasturage. No significant differences were detected among the treatments on pastures. 2. Parasitemia levels increased to $14.0\pm8.2$(parasite/1,000rbc) at 1 month after pasturage. 3. At the occurrence of tirst estrus and conception, the average age of the Holstein heifers was $14.3\pm1.9$ and $17.4\pm1.5$ months, respectively, and the average interval of estrus cycle was $20.6\pm1.0$ days. Howerer, there was no significant difference on reproductive efficiency among 3 treatments. 4. The outbreak of diseases were tick bane disease, pink eye, pneumonia, mastitis, gastroentitis, waterpoisoning ringworm papillon and atosis during pasturage period(may-october). These diseases were showed no significant difference among 3 treatments. 5. In conclusion, there are no significant difference on the reproductive effeciency and disease outbreak among three treatments.

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DEVELOPMENT OF MATDYMO (MULTI-AGENT FOR TRAFFIC SIMULATION WITH VEHICLE DYNAMICS MODEL) I: DEVELOPMENT OF TRAFFIC ENVIRONMENT

  • CHOI K. Y.;KWON S. J.;SUH M. W.
    • International Journal of Automotive Technology
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    • v.7 no.1
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    • pp.25-34
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    • 2006
  • For decades, simulation technique has been well validated in areas such as computer and communication systems. Recently, the technique has been much used in the area of transportation and traffic forecasting. Several methods have been proposed for investigating complex traffic flows. However, the dynamics of vehicles and diversities of driver characteristics have never been considered sufficiently in these methods, although they are considered important factors in traffic flow analysis. In this paper, we propose a traffic simulation tool called Multi-Agent for Traffic Simulation with Vehicle Dynamics Model (MATDYMO). Road transport consultants, traffic engineers and urban traffic control center managers are expected to use MATDYMO to efficiently simulate traffic flow. MATDYMO has four sub systems: the road management system, the vehicle motion control system, the driver management system, and the integration control system. The road management system simulates traffic flow for various traffic environments (e.g., multi-lane roads, nodes, virtual lanes, and signals); the vehicle motion control system constructs the vehicle agent by using various vehicle dynamic models; the driver management system constructs the driver agent capable of having different driving styles; and lastly, the integrated control system regulates the MATDYMO as a whole and observes the agents running in the system. The vehicle motion control system and driver management system are described in the companion paper. An interrupted and uninterrupted flow model were simulated, and the simulation results were verified by comparing them with the results from a commercial software, TRANSYT-7F. The simulation result of the uninterrupted flow model showed that the driver agent displayed human-like behavior ranging from slow and careful driving to fast and aggressive driving. The simulation of the interrupted flow model was implemented as two cases. The first case analyzed traffic flow as the traffic signals changed at different intervals and as the turning traffic volume changed. Second case analyzed the traffic flow as the traffic signals changed at different intervals and as the road length changed. The simulation results of the interrupted flow model showed that the close relationship between traffic state change and traffic signal interval.

Evaluation on Compressive Strength Development and Thermal Conductivity of Cement Pastes Containing Aerogels with Hydrophilic Surface Treatment (친수성 표면개질의 에어로겔을 혼입한 시멘트 페이스트의 압축강도 발현 및 열전도율 평가)

  • Ahn, Tae-Ho;Park, Jong-Beom;Yoon, Hyun-Sub;Yang, Keun-Hyeok
    • Journal of the Korea Institute of Building Construction
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    • v.18 no.1
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    • pp.51-57
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    • 2018
  • The objective of the present study is to examine the feasibility on the development of high-insulation concrete using aerogels with hydrophilic surface treatment. To prevent the segregation and enhance the dispersibility of agerogels in the cement pastes, the substrate of aerogels was modified to be hydrophobic property using surfactant. The modified aerogels were added from 0% to 100% of the cement volume at the interval of 25% under the constant cement content. Some cement pastes showed segregation phenomenon and flocculation of aerogels during mixing phase. The addition of aerogels decreased the compressive strength of cement pastes but enhanced the thermal conductivity. The thermal conductivity of pastes with 100% aerogels was lower by 43% when compared with that measured in the conventional paste. To improve the compressive strength and insulation capacity of concrete containing aerogels, a reliable surface treatment method of aerogels needs to be further investigated.

Interaction Between Bronchiolitis Diagnosed Before 2 Years of Age and Socio-Economic Status for Bronchial Hyperreactivity

  • Leem, Jong-Han;Kim, Hwan-Cheol;Lee, Ji-Young;Sohn, Jong-Ryeul
    • Environmental Analysis Health and Toxicology
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    • v.26
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    • pp.11.1-11.6
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    • 2011
  • Objects: The prevalence of asthma has increased in recent decades globally. The objective of the present study is to elucidate whether hospitalization for bronchiolitis in infancy and low socioeconomic status interact for bronchial hyperreactivity during teenage years. Method: We studied 522 children age 13-14 years attending schools in rural and urban areas to investigate the risk factors for bronchial hyperreactivity (BHR), defined as a provocation concentration of methacholine that causes a decrease of 20% ($PC_{20}$) in forced expiratory volume within 1 second. Clinical examination, skin prick test, spirometry, and methacholine challenge were performed on all study subjects, who provided written consent. We used multivariate logistic regression to investigate the risk factors for BHR, and analyze the interaction between hospitalization for bronchiolitis in infancy and low socioeconomic status. Results: Forty-six (10.3%) positive BHR cases were identified. In the multivariate logistic analysis, as independent predictors of BHR, adjusted odds ratio of bronchiolitis diagnosed before 2 years of age in low income families was 13.7 (95% confidence interval, 1.4 to 135.0), compared to reference group, controlling for age, gender, parental allergy history, skin prick test, and environmental tobacco smoke (ETS) exposure. Interaction was observed between bronchiolitis before 2 years old and low socioeconomic status on children's bronchial hyperreactivity (p-interaction=0.025). Conclusions: This study showed that bronchiolitis diagnosed before 2 years of age and low socioeconomic status interacted on children's bronchial hyperreactivity. Prevention of acute respiratory infection in early childhood in low socioeconomic status is important to prevent BHR as a precursor of asthma.

A Study on the Effects of Fuel Rail Pressure and Engine Speed on Gas Fuel System (연료레일 압력과 엔진 속도가 가스연료 시스템에 미치는 영향에 관한 연구)

  • Kwak, Youn-Ki
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.11 no.5
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    • pp.579-585
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    • 2018
  • This study is to figure out the fuel injection characteristics according to the injection pressure and engine speed in the fuel supply system for gas fuel. The fuel rail pressure was from 1.5 to 6.0 bar by 1.5 bar increment and engine speed was set 1,000 ~ 6,000 RPM at interval of 1000 RPM. Considering the real engine operation, the injection pulse width was set 2.5ms, 5.0ms, and 13.0ms which correspond low, mid and high load condition respectively. In conclusion, in case of 100cc fuel rail, 4.5 bar of injection pressure showed best performance and the minimum required injection quantity 53cc which guarantees engine output can be obtained in each 1000~ 6000 rpm engine speed.

An Efficient Real Time Processing Method for Frequently Updated Data (빈번한 변경이 요구되는 데이터의 효율적인 실시간 처리 기법)

  • Kim Jin-Deog;Jin Kyo-Hong;Lee Sung-Jin;Jung Hae-Won
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2006.05a
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    • pp.461-465
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    • 2006
  • Recently, the operator modules to control external devices are concerned about automatic management system to process continuously changed signals. They need a efficient data management with high reliability and real time processing. The characteristics of these data are a large volume, a short report interval and asynchronous report time. The typical queries of these systems consist of the current query to search the latest signal value, the snapshot query to search the signal value of a past time, the historical query to search the signal value of a past tine to current. In this paper, we propose the efficient method to manage the above signals by using a file structured database in QNX operating systems. The data communications among the devices are done by Profibus-FMS protocol and the file databases are used for adjusting monitoring frequency and storing signals. The file database adopts a delta version and a periodical back up in due consideration of the resource limit of a small storage and a low computing power in QNX COM(Cabinet Operator Module).

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Ultrasonic dissection versus electrocautery for immediate prosthetic breast reconstruction

  • Lee, Dongeun;Jung, Bok Ki;Roh, Tai Suk;Kim, Young Seok
    • Archives of Plastic Surgery
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    • v.47 no.1
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    • pp.20-25
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    • 2020
  • Background Ultrasonic dissection devices cause less thermal damage to the surrounding tissue than monopolar electrosurgical devices. We compared the effects of using an ultrasonic dissection device or an electrocautery device during prosthetic breast reconstruction on seroma development and short-term postoperative complications. Methods We retrospectively reviewed the medical records of patients who underwent implant-based reconstruction following mastectomy between March 2017 and September 2018. Mastectomy was performed by general surgeons and reconstruction by plastic surgeons. From March 2017 to January 2018, a monopolar electrosurgical device was used, and an ultrasonic dissection device was used thereafter. The other surgical methods were the same in both groups. Results The incidence of seroma was lower in the ultrasonic dissection device group than in the electrocautery group (11 [17.2%] vs. 18 [31.0%]; P=0.090). The duration of surgery, total drainage volume, duration of drainage, overall complication rate, surgical site infection rate, and flap necrosis rate were comparable between the groups. Multivariate analysis revealed that the risk of seroma development was significantly lower in the ultrasonic dissection device group than in the electrocautery group (odds ratio for electrocautery, 3.252; 95% confidence interval, 1.242-8.516; P=0.016). Conclusions The findings of this study suggest that the incidence of seroma can be reduced slightly by using an ultrasonic dissection device for prosthesis-based breast reconstruction. However, further randomized controlled studies are required to verify our results and to assess the cost-effectiveness of this technique.

Predictors of Acute Postoperative Urinary Retention after Transvaginal Uterosacral Suspension Surgery

  • Son, Eun-Joo;Joo, Eunwook;Hwang, Woo Yeon;Kang, Mi Hyun;Choi, Hyun Jin;Yoo, Eun-Hee
    • Journal of Menopausal Medicine
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    • v.24 no.3
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    • pp.163-168
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    • 2018
  • Objectives: To investigate the rate of postoperative urinary retention (POUR) and identify the risk factors for this complication in women who underwent transvaginal uterosacral suspension surgery. Methods: A retrospective chart review was conducted for 75 women who underwent transvaginal uterosacral suspension surgery with vaginal hysterectomy, repair of cystocele, and levator myorrhaphy with/without transobturator anti-incontinence surgery. POUR was defined as a need for continuous intermittent catheterization on the third day subsequent to removal of the urethral indwelling catheter. Results: Acute POUR was reported in 18 women (24.0%). Thirty-six of the 75 patients (48.0%) had undergone anti-incontinence surgery. Crude analysis revealed significant association between the following variables and the risk of POUR: hypertension, the lower average flow rate in the pressure-flow study (PFS), greater post-void residual (PVR) urine volume in PFS, and PVR >30% of the total bladder capacity (TBC) in PFS. In the logistic regression analysis, PVR >30% of the TBC in PFS was identified as the only significant predictor of POUR (odds ratio, 15.4; 95% confidence interval, 2.5-90.9; P = 0.003). Conclusions: The PVR >30% of the TBC in PFS was identified as the only predictive factor of acute POUR in women who underwent transvaginal uterosacral suspension surgery.

Estimation of Site Index Equation for Pinus densiflora at Mt. Osu Region using Schnute Growth Function (Schnute 생장함수를 이용한 오서산지역 소나무림의 지위지수 추정)

  • Pyo, Jung-Kee;Lee, Young-Jin;Son, Yeong-Mo;Lee, Kyeong-Hak;Moon, Hyun-Shik
    • Journal of agriculture & life science
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    • v.43 no.4
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    • pp.9-14
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    • 2009
  • The purpose of this study was to estimate height growth pattern and to derive site index equation for Pinus densiflora grown at Mt. Osu region, Chungnam. A total of 21 repre - sentative trees from the established temporary plots around Boryeng and Cheongyang regions were destructively sampled to measure diameter, height, volume growth per 1-year interval by using of DTRS- 2000 measurement instrument. The Schnute growth function was select ed for height growth prediction using 181 height-age paired observations and derived anamorphic base age invariant site index curves (base index age 30 years). The fitted index and the asymptotic value of Schnute model indicated both 0.96 and 10.8 meter, respectively. The results suggested in this study could be very useful to understand the height growth pattern and productivity of the site quality on Pinus densiflora grown at Mt. Osu region, Chungnam.